<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      let hire = [1500, 2000, 1200, 2500,3800];
      console.log(hire.length);

      document.write (`平均数: ${(+hire[0] + hire[1] + hire[2] + hire[3] + hire[4]) / (hire.length)} `)
    </script>
  </body>
</html>
